Quick release locking mechanism



Fel 17, 1953 F. R. GARDNER QUICK RELEASE LOCKING MECHANISM Filed July 5,A 1949 FIG. 1..

FIGB.

FRED R. GARDNER Zmventor Patented Feb. 17, 1953 UNITED STATES FTENT OFFICE 2,e2s,s54 Y QUICK REL-msn LocKiN'G MECHANIsr/ `lred R Gardner, Wichita, Kans. Application Jelly s, 1949, serial No. 163,140

1 claim. (c1. 4 rs'v---tsl This invention relates to van improvement in mechanisms for locking telescoping tubular members in selected relative positions, and for quickly releasing them for movement to newly selected` positions, and re-locking them.

It is the chief object oi the invention to provide a simple mechanism which will prevent relative movement of two teieseopmg tubes in either direction Without requiring notches or the like in either of the two tubes.

Itis another object to provide such a device which `does not require any movement of the tubes after Athey have been placed in the desired relative positions in order to set or firmly lock the mechanism.

Another object is to provide a tube locking mechanism which will not scar or bite into the surface of either telescoping tube.

An additional object is to provide a mechanism of this type which does not require the longitudinal slotting of either of the telescoping tubes.

Another object is to provide a locking mechanism which can be adapted to work equally well on telescopng tubes of varying cross sectional shapes, such as square, hexagonal, etc.

The invention will be more clearly understood when the following description is read in connection with the accompanying drawings, in which:

Fig. 1 is a top plan View Vof a locking mechanism embodying the invention, installed on two telescoping tubes;

Fig. 2 s a sectional view along the line 2 2 OfFig. 1;

Figs. 3 and 4 are front and side views respectively of a part of the rlocking mechanism illustrated Fig. 5 is a transverse sectional view taken along the line 5-5 of Fig. 1; and

Fig. 6 is a bottom plan View of the locking mechanism release handle and its associated spring.

Referring to the drawings, the two telescoping tubes are identified by the numerals I and II. A collar I2 is welded or otherwise rigidly secured to one end of the outer tube I. This collar is provided with a pair of spaced outwardly projecting ears I3 and It, which lie in planes parallel Y to the longitudinal tube axis. The adjacent inner surfaces of these ears are drilled out, as 4clearly shown in Fig. 1, and the drilled hole continues through the collar I2, substantially at right angles to the longitudinal axis thereof, to form a guide for a friction shoe I which is slidable axially in the guide hole.

The ears It and areprovided with trans'- versely alined holes whiehlie in apositionjs'paced longitu'dinallyfrom the shoe I5. One of these holes is threaded. l

Arcrfsho'e operating lever type handle 'I6 is pivotallyjmounted between the ears I3 and le on a pivot pin Il, which passes through the alin'ed holes inthe :ears and 'hasoneof 'its ends threaded and :seated in a complementary threaded hole in one ear, as clearly shown fin Fig. 5. a a

` 'Ihedetails vin the construction of the shoe are clearly vshown in Figs. -3 and 4'. VIts main body portion 'i8 is'c'ircular in Vcross section, its bottom surface I9 is concavely arcuate to t snugly against the outer surface of the inner tube II, its upper end is slotted, as at 2t, to receive the shoe operating end of the lever I6, and its upper end is also truncated at an angle, as at 2I (Fig. 4), to lie substantially in the same plane as the sloping surface 22 (Fig. 2) at the pivoted end of the lever. These last mentioned sloping surfaces are primarily to improve the appearance of the device and are not necessary to its proper functioning.

The lever type handle has an integral laterally disposed semi-cylindrical lug 23 which is positioned to Contact the bottom of the slot 20 in the shoe I5. Through this lug the lever serves to apply frictional pressure on the shoe to force itsarcuate surface I9 firmly against the adjacent surface of the tube II. This pressure, substantially at right angles to the longitudinal axis of the tube I I, is provided by a leaf type spring 24, one end of which is seated in a notch 25 in the handle I6, and the other end of which bears against the outer surface of the tube I, as Shown, at a point beneath the opposite end of the handle.

Integral lugs 26 and 27 (Fig. 6), on the nether surface of the handle I 6 seat in appropriately located notches in the opposite Aside edges of the spring 24, and serve to keep the forward end of the spring centered with relation to the handle I6. The opposite end of the spring 2li is kept centered by being made transversely arcuate as indicated at 28. to t firmly against the surface of tube I0.

From the construction described, it will be seen that the spring 24 urges the handle I6 in a clockwise direction (as viewed in Fig. 2)` about its pivot pin I1, thus applying strong inward pressure on the shoe I5, and urging it into firm frictional contact with the periphery of the tube I I. By encircling the outer tube I 0 and the handle I6 with the hand and squeezing, the handle is moved slightly counterclockwise, thus relieving Vthe shoe of pressure, and permitting the tube Il to slide easily in either direction with relation to the tube l0. When hand pressure on the handle is released the shoe l5 is again moved into frictional contact with the tube H, locking the two tubes against relative movement. The outer edges of the arcuate portion IS of the shoe l5 are preferably chamfered slightly and buifed to prevent the shoe from scratching or otherwise marring the surface of the inner tube Il.

Having described the invention with sucient clarity to enable those familiar with the art to construct and use it, I claim:

A mechanism for frictionally and releasably locking two telescoping members against relative longitudinal movement, the receiving one of said members being tubular, and the inner member being cylindrical and having a smooth outer surface, said mechanisms comprising: a cylindrical sleeve or collar fixed on the outer surface of the receiving member; aligned circular apertures of identical size and shape through said collar and through the wall of the outer telescoping member forming a laterally disposed guideway; a shoe of cylindrical cross section slidably fitting in said guideway for reciprocating movement into and out of contact with the smooth cylindrical surface of the inner telescoping member, the outer end of said shoe projecting outwardly beyond said collar; a bifurcated lever mounting bracket carried by said collar adjacent the aperture therein; a lever pivotally mounted intermediate its ends between the furcations of said bracket the distance from the pivot point to either end of the lever being greater than the distance from the pivot point to the adjacent surface of the outer telescoping member; an intertting tongue and groove connection between one end of said lever and the outer end of said shoe to prevent shoe rotation in its guideway; and an elongated curved leaf spring having one end secured to said lever adjacent its pivot point, the opposite end of said spring being curved toward and into free sliding contact with the exterior surface of the outer telescoping member at a point remote from said pivot point, an intermediate portion of said spring contacting an intermediate portion of the lever and urging it to pvot outward in a direction to force the shoe contacting end of the lever against the outer end of said shoe.

FRED R. GARDNER.

CITED `The following references are of record in the le of this patent:

UNITED STATES PATENTS 

